Electron tube structure



Nov. 14, 1950. S I E JR 2,529,820

ELECTRON TUBE STRUCTURE Filed May 23, 1949 FIG.2

I I [g 5 l J M" l N PU T OUTPUT o o O Q 0 O 0 O O D D. 1- D E o HEATE 7 R55 157cm tl- J I) D a D.

Z l- I) ANODE.

, GRI D ELECTRODES CATHODE DE INVENTOR.

Patented Nov. 14, 1950 /,//EIIFQOTRON TUBE STRUCTURE "iiose h c. Smiley, Jr., Philadelphia, Pa., assignor of one-half to Donald T. Wilson, Philadelphia,

Application May 23, 1949, Serial No. 94,910

12 Claims. (Cl. 250-275) This invention relates to electron tubes and more particularly to a unique arrangement of two independent cathodes in combination with three electrodes contained within the enclosure formed by the control-grid and designed to obtain a better control of the electron flow from the cathodes to control-grid and anode or plate and to prevent or minimize the coupling of the input circuit with the output circuit, when used with specially designed circuits as hereinafter described, and thus stabilize the performance of the tube in radio, telephone relay and television circuits.

In the operation of radio circuits, one of the faults encountered is that of feed-back of plate current to control-grid, when the control-grid is positive on one-half of the cycle of the input signal, causing the plate current to feed back through the control-grid circuit, through input coil to the negative side of plate circuit, causing interference to the incoming signal and resulting in unbalance in the circuit and distortion in the output signal. Thus far, in an endeavor to overcome this eiTect, many schemes have been tried, among which are the' screen-grid, elements known as suppressors, negative bias and the like, and my present invention has been designed to overcome these obstacles'by a better control of the electron stream or flow emanating from the cathodes and the path it follows to the controlgrid and through the control-grid spaces to the anode, or plate. This is accomplished through the special arrangement of the cathodes in their direct relation to the newly added three electrode elements contained within the enclosure formed by the control-grid to form a distinct combination with the control-grid and anode, or plate. Space charge within the tube is likewise minimized with this construction, as the electrodes become positive when the grid goes negative, thereby attracting the negative electrons which may happen to remain in space within the grid enclosure. Likewise, when grid goes positive the electrodes are at negative potential, resulting in' a concentration of the electron stream and lowering the resistance to the flow of current through electron stream from anode, or plate,-

r is also made at this point withground.

explanation deals with connections to the Var1ous directly heated cathodes 4 and 5 in linear formation. In practice the three electrodes would 'be' connected to a common pin and each cathode to its respective pin at the base of the tube.

Fig. 2 shows this electrode-cathode construcelements to their respective prongs, each'repre-' sented b the accepted designation of radio symbo1s,'that 0f the electrodes being suggested sy'mbols.

Fig. 6 shows a schematic circuit diagram employing the combination of elements described and which I have designated an isolated grid circuit. One of the terminals of the input coil is connected to the control-grid 6 and the reverse terminal connected to cathode 4. Electrodes I, 2 and 3 being connected to a common pin at base of tube, are also connected'toindividual pin of cathode 4 externally. While cathode 4 has been chosen for illustration, either cathode can be used and the electrodes connected thereto, externally. current supply is connected to one side of primary of output coil, while other side of primary is [connected to anode, or plate. The minus side of B current supply is connected to cathode 5-lat' its individualpin at base of tube. Connection elements as being accomplished externally, or from the various terminals of the socket in which the completed tube is inserted.

It should be noted that no negative bias is provided, as in the case of the accepted resistorcondenser method. It is also assumed that the heaters of cathodes are in circuit with A supply.

This constitutes a simple radio receivingcircuit, the function of which, with the newly designed tube described, would be as follows:

With the cathodes heated and the B currentsupply in circuit, negative electrons emanating from the cathode pass through vacuum to the positive anode or plate. When an incoming signal is impressed on the control-grid 6, i. e., on Y The positive side of B This I grid circuit cathode 4 and also between catho 5 and control-grid 6, causing stored energy in control-grid circuit to pass to ground through electron stream from control-grid 6 to cathode 5, thereby freeing the grid circuit of this stored energy and prevent interference to the succeeding incoming positive cycle. Also, when the control-grid 6 is positive, the electrodes are negative and as positioned, concentrate the flow of electrons from the cathodes to lower the'resistance to current flow between the cathodes and controlgrid and plate, thereby increasing current flow in B circuit. When the control-grid 5 goes negative on reverse side of cycle, it repulses' electron flow from cathode 5 to anode and cathode 4 to control-grid, reducing current in B circuit. As is known, it is the variation in the flow of B curre1lt,.caused by the varying potential applied to the control-grid, which results in the desired signal in the plate circuit. At the time the control-grid goes negative, the grid cathode 4' goes positive and further restricts the flow of e ectrons to the plate or anode by diverting the negative electrons to the electrodes, .which are also positive in relation to the grid. This also relieves the grid circuit of its stored energy by reason of the electron stream flowing from cathode 5 to electrodes-and thence to ground. These electrodes l 2 and 3, when positive, also relieves tube of any spacecharge within the grid enclosure, as the free electrons are drawn to the positive electrodes and add to the concentration of electrons between the positive electrodes and cathode 5.

In this circuit arrangement, it can be seen that B current flow would be restricted to the e ectron flow between B circuit cathode 5 and anode land not pass to positive controlrid 6, there being no outlet for such current through control-grid 6. Hence B circuit is kept from the grid circuit and latter circuit used only for signal variation.

Fig. 7 is a modified circuit, in which the three electrodes I, 2 and 3, are connected externally to cathode 5 and cathode 4 connected to cathode 5 through a resistor, reverse end of grid coil going direct to cathode 4. While this circuit mi ht not entirely eliminate feed-back as in the case of circuit in Fig. 6, the B current can better be confined'to its own circuit, anode to cathode 5, rather than pass to control-grid, when positive and thence to cathode 4 due to the resistance inserted between the two cathodes.

Fig. 8 is a further circuit modificat on, in which the whole assembly (the three electrodes I, 2 and 3 and the interposed cathodes 4 and 5) functions as one and wou d be like the conventional circuits, with the exception that an improved electron flow would be obtained when grid goes posi-' tive and cathodes negative. which, along with the negative potential on the three electrodes, would concentrate the electron flow from the cathodes to anode and thus offer less resistance to current flow from anode to cathodes.

I am aware that the heated cathode, grid and anode, or plate, are being used in conventional tube design, but it is the combination of these elements with the three electrodes i, 2 and 3, arranged in a specific manner which brings about a novel performance of the electrons in an electron tube and thus better results in radio recep- 4 tion or in such circuits where the employment of electron tubes is essential.

In view of the disclosure above, While I do not lay claim to the indirectly heated cathode, con- 5 trol-grid or anode in themselves, I do base my claims on the three newly added electrodes and their combination with two independent functioning cathoges; with a further combination with a control-grid and anode. I therefore here- 10 inafter set forth the following claims to the combination mentioned, viz:

1. In an electron tube of a type applicable to various circuit arrangements and the use ofaseparate heated cathode in the grid and anode circuits, comprising a control-grid and encircling anode, a structure positioned within enclosure formed by said control-grid, parallel to and in.

isolated relation to said control-grid, of three relatively spaced grid circuit unheated cathodes with an interposed grid circuit indirectly heated cathode and an interposed anode circuit indirectly heated cathode, said grid circuit unheated cathodes co-acting with said grid circuit indirectly heated cathode at cathode end of grid circuit to obtain a grid circuit separate from anode circuit through electron stream within tube envelope.

2. In an electron tube of a type applicable to various circuit arrangements and the use of a separate heated cathode in the grid and anode circuits, comprising a control-grid and encircling anode, a structure positioned within enclosure formed by said control-grid, parallel to and in isolated relation to saidcontrol-grid, of three relatively spaced grid circuit unheated electrodes with an interposed grid circuit indirectly heated cathode and an interposed anode circuit indirectly heated cathode, said grid circuit unheated electrodes co-acting with said grid circuit indirectly heated cathode at cathode end of grid circuit to obtaina grid circuit separate from anode circuit through electron stream within tube envelope.

3. In an electron tube of a type applicable to various circuit arrangements and the use of a :5 separate heated cathode in the grid and anode circuits, comprising a control-grid and encircling anode, a structure positioned within'enclosure.

formed by said control-grid, parallel to and in isolated relation to'said'control-grid of a grid circuit indirectly heated cathode and an anode circuit indirectly heated cathode, relatively spaced, with an interposed grid'circuit unheated cathode, said grid circuit unheated cathode coacting with said grid circuit indirectlyheated. cathode at cathode end of grid circuit to obtain &

anode, a structure positioned within enclosure 7 'formed by said control-grid, parallel to and in isolated relation to said control-grid of a grid circuit indirectly heated cathode and'an anode circuitindirectly heated cathode, relatively spaced, with an interposed grid circuit unheated electrode, said grid circuit unheated electrode co-acting with said grid circuit indirectly heated cathode at cathode end of grid circuit to obtaini a grid circuit separate from anode circuit-through electron stream within tube envelope.

5. In an electron tube of a type applicable to various circuit arrangements and 'the use of av se'parateheated "cathode in the grid andanode" circuits, comprising a control-grid and encircling anode, a structure positioned within enclosure formed by said control-grid, parallel to and in isolated relation to said control-grid, of three relatively spaced coacting unheated cathodes in linear formation, having connection with a common terminal outlet, with an interposed indirectly heated grid circuit cathode and an interposed indirectly heated anode circuit cathode, each having connection with its respective terminal outlet, said unheated cathodes and the interposed indirectly heated grid circuit and anode circuit cathodes being disposed diametrically, parallelly and in isolated relation. i

6. In an electron tube of a type applicable to various circuit arrangements and the use of a separate heated cathode in the grid and anode circuits, comprising a control-grid and encircling anode, a structure positioned within enclosure formed by said control-grid, parallel to and in isolated relation to said control-grid, of three relatively spaced coacting unheated electrodes in linear formation, having connection with a common terminal outlet, with an interposed indirectly heated grid circuit cathode and an interposed indirectly heated anode circuit cathode, each having connection with its respective terminal outlet, said unheated electrodes and the interposed indirectly heated grid circuit and anode circuit cathodes being disposed diametrically, parallely and in isolated relation.

7. In an electron tube of a type applicable to various circuit arrangements and the use of a separate heated cathode in the grid and anode circuits, comprising a contro1-grid and encircling anode, a structure positioned within enclosure formed by said control-grid, parallel to and in isolated relation. to said control-grid, of an indirectly heated grid circuit cathode and an indirectly heated anode circuit cathode, relatively spaced and each having connection with its respective terminal outlet, with an interposed unheated cathode, having connection with a single terminal outlet, said indirectly heated grid circuit and anode circuit cathodes and the interposed unheated cathode being disposed diametrically, parallelly and in isolated relation.

8. In an electron tube of a type applicable to various circuit arrangements and the use of a separate heated cathode in the grid and anode circuits, comprising a control-grid and encircling anode, a structure positioned within enclosure formed by said control-grid, parallel to and in isolated relation to said control-grid, of an indirectly heated grid circuit cathode and an indirectly heated anode circuit cathode, relatively spaced and each having connection with its respective terminal outlet, with an interposed unheated electrode, having connection with a single terminal outlet, said indirectly heated grid circuit and anode circuit cathodes and interposed unheated electrode being disposed diametrically, parallelly and in isolated relation.

9. In an electron tube of a type applicable to various circuit arrangements and the use of a separate heated cathode in the grid and anode circuits, comprising a control-grid and encircling anode, a structure positioned within enclosure formed by said control-grid, parallel to and in isolated relation to said control-grid, of three relatively spaced coacting unheated grid circuit cathodes in linear formation, having connection with a common terminal outlet, with two interposed independently acting indirectly heated cathodes, each having connection with its respective terminal outlet, said unheated grid circuit cathodes and indirectly heated cathodes being disposed diametrically, parallelly and in isolated anode, a structure positioned within enclosure formed by said control-grid, parallel to and in isolated relation to said control-grid, of two relatively spaced independently acting indirectly heated cathodes, each having connection with its respective terminal outlet, with an interposed unheated grid circuit cathode having connection with a single terminal outlet, said indirectly heated cathodes and unheated grid circuit cathode being disposed diametrically, parallelly and in isolated relation.

11. In an electron tube of a type applicable to various circuit arrangements and the use of a separate heated cathode in the grid and anode circuits, comprising a control-grid and encircling anode, a structure positioned within enclosure formed by said control-grid, parallel to and in isolated relation to said control-grid, of three relatively spaced coacting unheated grid circuit cathodes in linear formation, having connection with a common terminal outlet, with an interposed indirectly heated grid circuit cathode and an interposed indirectly heated anode circuit cathode, each having connection with its respective terminal outlet, saidunheated grid circuit cathodes and interposed indirectly heated grid circuit and anode circuit cathodes being disposed diametrically, parallelly and in isolated relation.

12. In an electron tube of a type applicable to various circuit arrangements and the use of a separate heated cathode in the grid and anode circuits, comprising a control-grid and encircling anode, a structure positioned within enclosure formed by said control-grid, parallel to and in isolated relation to said control-grid, of an indirectly heated grid circuit cathode and an indirectly heated anode circuit cathode, relatively spaced and each having connection with its respective terminal outlet, with an interposed unheated grid circuit cathode, having connection with a single terminal outlet, said indirectly heated grid circuit and anode circuit cathodes and the interposed unheated grid circuit cathode being disposed diametrically, parallelly and in isolated relation.

JOSEPH C. SMILEY, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,224,649 Harris Dec. 10, 1940 2,248,712 Litton July 8, 1941 2,295,816 Wilson Sept. 15, 1942 2,459,072 Haines Jan. 11, 1949 FOREIGN PATENTS Number Country Date 191,077 Switzerland Aug. 16, 1937 

